Soil water retention, air flow and pore structure characteristics after corn cob biochar application to a tropical sandy loam

• Published in: Geoderma 2017-12, Vol.307, p.189-197
• Main Authors: Amoakwah, E., Frimpong, K.A., Okae-Anti, D., Arthur, E.
• Format: Article
• Language: English
• ISSN: 0016-7061; 1872-6259
• DOI: 10.1016/j.geoderma.2017.08.025

Soil structure is a key soil physical property that affects soil water balance, gas transport, plant growth and development, and ultimately plant yield. Biochar has received global recognition as a soil amendment with the potential to ameliorate the structure of degraded soils. We investigated how corn cob biochar contributed to changes in soil water retention, air flow by convection and diffusion, and derived soil structure indices in a tropical sandy loam. Intact soil cores were taken from a field experiment that had plots without biochar (CT), and plots each with 10tha−1 (BC-10), 20tha−1 without or with phosphate fertilizer (BC-20 and BC-20+P respectively). Soil water retention was measured within a pF range of 1 to 6.8. Gas transport parameters (air permeability, ka, and relative gas diffusivity, Dp/D0) were measured between pF 1.5 and 3.0. Application of 20tha−1 led to significant increase in soil water retention compared to the CT and BC-10 as a result of increased microporosity (pores